Expandable surgical implants and methods of using them

ABSTRACT

Disclosed herein are expandable surgical implants that may be expanded one or more times by directly or indirectly uncinching one or more expansion loops. Use of the expandable surgical implant permits a physician to expand, with minimal invasion, a surgical implant that was over-tensioned by a surgeon during implantation or became over-tensioned due to changes in the patient&#39;s anatomy.

TECHNICAL FIELD

This invention generally relates to expandable surgical implants andmethods of using such expandable surgical implants.

BACKGROUND INFORMATION

Numerous medical disease conditions that result from prolapse ofinternal organs and/or anatomical structures may be treated by providingsupport to the area of prolapse with a surgical implant such as a sling,a patch, or a mesh. Such implants are useful to treat, for example,stress urinary incontinence in female patients.

Various physiological conditions cause urinary incontinence in women.Stress urinary incontinence generally is caused by two conditions thatoccur independently or in combination, Intrinsic Sphincter Deficiency(ISD) and Bladderneck Hypermobility. ISD is a condition where theurethral sphincter valves fail to coapt properly. When functioningproperly, the urethral sphincter muscles relax to enable the patient tovoid, and the sphincter muscles are otherwise constricted to retainurine. ISD may cause urine to leak out of the urethra during strainingactivities. Hypermobility is a condition where the pelvic floor isweakened or damaged causing the bladder neck and proximal urethra todescend in response to increases in intra-abdominal pressure. Whenintra-abdominal pressure increases (due, for example, to strainresulting from coughing), the hypermobility condition may cause urineleakage. Some women suffer from a combination of ISD and hypermobility.

The methods for treating stress urinary incontinence include placing animplant to provide support, elevation, or a “back stop” to the bladderneck and proximal urethra. Providing support to the bladder neck andproximal urethra maintains the urethra in the normal anatomicalposition, elevation places the urethra above the normal anatomicalposition, and the “back stop” prevents descent according to theso-called hammock theory.

One problem encountered following surgical intervention using an implantsuch as a sling or a patch to treat urinary incontinence is urinaryretention resulting from excessive tension applied to the urethra.Overtensioning may also cause pressure necrosis and/or urethral erosion.One approach to alleviate these problems entails stretching the implantby inserting a catheter into the urethra and applying downward force.This procedure is imprecise and is contraindicated for patients with ISDas it may further damage the urethral sphincter. Another more invasiveapproach entails surgically removing the implant. Removal of such asurgical implant, which may require dissection, may cause irreparabledamage to an already weakened or damaged pelvic floor. Accordingly,there is a need in the surgical arts for a surgical implant that may beexpanded while positioned in the body. There is a further need for aprecise and minimally invasive surgical method for expanding a surgicalimplant after it has been placed in the body.

SUMMARY OF THE INVENTION

It is an object of the invention to allow for expansion of a surgicalimplant while the implant is positioned in a body. Thus, the presentinvention provides for a surgical implant that may be expanded one ormore times after being placed in the body, thereby providing a physicianwith the ability to loosen a surgical implant that was over-tensionedwhen placed by the surgeon and/or has become over-tensioned because ofchanges in the patient's anatomy. Thus, the expandable implant of theinvention may be used, for example, in a suburethral sling procedure totreat female urinary incontinence by stabilizing the urethra, and laterexpanded if the patient suffers from urinary retention resulting fromanatomical changes such as, for example, weight gain and/or pregnancy.

In one aspect, an expandable surgical implant having the features of thepresent invention may comprise a length of biocompatible material havingat least one expansion loop positioned along the length of thebiocompatible material and to one side of the center of the length(i.e., the central perpendicular axis of the implant).

In some embodiments, the expandable surgical implant may comprise anequal number of expansion loops that are positioned on either side ofthe central perpendicular axis; for example, the expandable surgicalimplant may comprise two, four, or six expansion loops positioned alongthe length of the biocompatible material and lateral to the centralperpendicular axis. The expansion loops may each comprise at least onepair of control element attachment sites and at least one controlelement, such as a fastener, which is used to control the timing anddegree of expansion. The pair of control element sites may be positionedon one side of the central perpendicular axis. The control elements maybe attached to the control element sites and cinched so that the controlelement sites into are drawn into close proximity, thereby shorteningthe implant and facilitating its later expansion. In some preferredembodiments, a first control element site is positioned a distanceranging from 3-20 mm lateral to the central perpendicular axis of thelength of biocompatible material and a second control element site ispositioned a distance ranging from 3-12 mm further from the centralperpendicular axis than the first control element. In particularlypreferred embodiments, the second control element site is positioned adistance of about 5 mm further from the central perpendicular axis thanthe first control element site.

In some embodiments, the control element is a fastener such as amonofilament suture, a multifilament suture, an elongate length ofbiocompatible material, or a surgical staple. The control elementattachment sites maybe reinforced to add resiliency to the implant atthe expansion loop site or sites; for example, the control attachmentsite may be reinforced with an eyelet or an additional layer ofbiocompatible material.

In some embodiments, the control element is radio-opaque to facilitateindirect visualization of the control element site by a physician usingthe expandable surgical implant. When the control element isradio-opaque, it may be visualized using an instrument such as afluoroscope. To facilitate direct visualization, the control element maya different color than the biocompatible material. Such direct and/orindirect visualization is particularly useful when expanding thesurgical implant of the invention following implantation.

The control element may comprise bioabsorbable material so that itdissolves without physician intervention to thereby permit the implantto expand at the predetermined time. In alternative embodiments thecontrol element is adapted to decompose upon application of externalstimuli, thus permitting a physician to expand the implant at anydesired time. For example, the control element may be adapted todecompose upon exposure to a localized low energy source or a chemicalagent. The localized low energy may be in the form of, for example,ultrasonic waves, radio waves, microwaves, and ultraviolet radiation.The expandable surgical implant may comprise multiple expansion loopsassociated with control elements adapted to decompose upon theapplication of separate external stimuli. In such embodiments, theexpandable surgical implant may be expanded multiple times by applyingmultiple stimuli (e.g., different forms or intensities of energy) thatdecompose different control elements. For example, the expandablesurgical implant may be expanded a first time by applying one stimulusthat decomposes a first control element and, possibly, a second controlelement, and subsequently expanded further by applying a separatestimulus that decomposes a third control element and, possibly, a fourthcontrol element.

In some embodiments, the expandable loop comprises multiple layers ofbiocompatible material of unequal length. The layers of biocompatiblematerial may, for example, be stacked in increasing length. In preferredembodiments, each layer of biocompatible material is about 2 mm to about10 mm shorter than the adjacent longer layer in the stack ofbiocompatible material. In particularly preferred embodiments, the eachlayer of biocompatible material is about 5 mm shorter than the adjacentlonger layer of biocompatible material in the stack. Furthermore, thelayers of biocompatible material are preferably positioned a distanceranging from 3-20 mm lateral to the central perpendicular axis. Inparticularly preferred embodiments, the layers of biocompatible materialare 6 mm lateral to the central perpendicular axis.

In some embodiments, the expandable surgical implant comprises a lengthof biocompatible material that is synthetic, such as, for example,nylon, polyethylene, polyester, polypropylene, one or morefluoropolymers such as polyfluoroethylene and/or combinations thereof.In alternative embodiments, the length of biocompatible materialcomprises natural material. In further alternative embodiments, thelength of biocompatible material comprises a combination of natural andsynthetic material. In one particular embodiment, the expandablesurgical implant comprises a length of biocompatible material having acentral portion comprising natural material and the first end portionand second end portion comprise synthetic material.

The expandable surgical implant may comprise a visual indicator locatedalong at least a portion of the central perpendicular axis. The visualindicator may comprise, for example, a surgical dye applied along thecentral perpendicular axis. The visual indicator may alternativelycomprise a radio-opaque material woven into the biocompatible materialalong the central perpendicular axis.

In some embodiments, the length of biocompatible material is elongate(e.g., rectangular) in shape. For example, the length of biocompatiblematerial may be about 44 cm to 47 cm long with all expansion loopscinched.

In another aspect, the present invention is directed to methods oftreating urinary incontinence. An expandable surgical device comprisingat least one expansion loop is implanted into a patient to support theurethra. The device is then expanded to reduce the amount of tensionapplied to the urethra. Thus, the invention provides a surgeon with theability to loosen a surgical implant (e.g., to ameliorate urinaryretention caused by an excessively taut implant or to accommodate apregnancy).

In some embodiments, an expandable surgical device is implanted into apatient and subsequently loosened. The implanted device may comprise abiocompatible material having a length, a central perpendicular axisnormal to the length and located substantially equidistant from the endsof the device, and at least one expansion loop into a patient. Theexpansion loop(s) are positioned along the length of the biocompatiblematerial lateral to the central perpendicular axis.

In some embodiments, the expandable surgical device is implanted beneaththe bladder neck; for example, the expandable surgical device may beimplanted beneath the first third or the central third of the urethra.The device may be affixed to an anatomical structure selected by thesurgeon according to the particular anatomy of the patient. The devicemay be attached, for example, to fascia, bone, ligament, and/or muscle.The method of invention may further comprise aligning the centralportion of the device beneath the urethra using a visual indicatorlocated along at least a portion of the central perpendicular axis.Expansion may be accomplished by severing the shorter of at least twolayers of material of unequal length incorporated into the biocompatiblematerial. Alternatively, expansion may be accomplished by severing acontrol element (e.g., a fastener) which holds two laterally distantportions of the implant in close proximity (i.e., creates a loop).

Thus, in other embodiments, expansion is accomplished by uncinching thecontrol element, which holds in close proximity a pair of controlelement sites that are located on the on one side of the central axis.The uncinching may be accomplished by severing the control element. Thecontrol element may be severed using mechanical means such as, forexample, a scalpel. Alternatively, the uncinching may be accomplished byapplying an external stimulus to cause the control element to decompose.For example, localized low energy (e.g., ultrasonic waves, radio waves,microwaves, and/or ultraviolet radiation) may be applied to the controlelement to stimulate decomposition and severance of the control element,which in turn permits the expandable surgical implant to expand. In someapproaches the control element is radio-opaque and may be visualizedwithout incision by, for example, fluoroscopy. The foregoing methodsthat, preferably, do not require an incision to sever the controlelement facilitate adjustment of an expandable surgical implant withminimal or no surgical invasion.

In some embodiments, the expandable surgical implant may be expandedmultiple times by uncinching multiple expandable loops. In oneparticular embodiment, the expandable surgical implant is expandedmultiple times by the application of a combination of different externalstimuli which decompose different control elements causing the expansionloops attached by the different control elements to become uncinched.This aspect of the method of the invention affords the physician greatflexibility in adjusting expandable surgical implants; the physicianmay, for example, select one of several expansion loops to expandaccording to position or size by applying the external stimulus specificto decompose a specific control element.

These and other features, aspects, and advantages of the presentinvention will become better understood with reference to the followingdescription and appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention.

FIG. 1 is a plan view of one disclosed embodiment of an expandableimplant of the invention.

FIG. 2A is a side view of the cinched-loop embodiment of the expandableimplant of the invention.

FIG. 2B is a plan view of the cinched-loop embodiment of the expandableimplant of the invention.

FIG. 2C is a side view of a cinched-loop showing the control elementsevered to expand the length of the implant.

FIG. 3A is a plan view of the stacked-layers embodiment expandableimplant.

FIG. 3B is a side view of the stacked-layers embodiment of theexpandable implant of the invention, which shows three stacked layers.

FIG. 3C is an elevation of the stacked-layers embodiment of theexpandable implant of the invention showing one layer severed to expandthe length of the implant.

FIG. 4 is a plan view of the embodiment of the expandable implant thatincludes eyelets positioned near the ends of the surgical implant and avisual indicator positioned in the center of the surgical implant.

FIG. 5 is a sagittal section of a female pelvis illustrating anexpandable surgical implant used in a procedure to treat female urinaryincontinence where the implant is anchored to the posterior pubic bonecephalad to the inferior edge.

FIG. 6 is a sagittal cross section of a female pelvis illustrating anexpandable surgical implant used in a suburethral sling procedure totreat female urinary incontinence where the implant is anchored to theposterior surface of the pubic bone approximately midway between theinferior and superior edges.

FIG. 7 is a sagittal cross section of a female pelvis illustrating anexpandable surgical implant used in a suburethral sling procedure totreat female urinary incontinence where the implant is anchored to thesuperior surface of the pubic bone.

FIG. 8 is a superior view of the pelvic floor of the embodiment shown inFIG. 7.

DESCRIPTION

Referring to FIG. 1 an expandable surgical implant 100 of the presentinvention can be made of a length, “1, of biocompatible material 102which includes a first end 104 and a second end 106 positioned oppositeto the first end 104, and a central perpendicular axis 108 locatedmidway between the ends 104, 106. The expandable surgical implant 100 ofthe invention also comprises at least one expansion loop 110. Inpreferred embodiments, an equal number of expansion loops are preferablypositioned on either side of the central perpendicular axis 108 (asshown in FIG. 1). In some embodiments the expandable surgical implant100 may further comprise a visual indicator 118 located along thecentral perpendicular axis 108. The visual indicator shown in FIG. 1comprises a pair of lines 118 and 118′ positioned on either side of thecentral perpendicular axis 108. The expandable surgical implant 100 maycomprise multiple (e.g., one to ten) expansion loops 110. In preferredembodiments, the expandable surgical implant 100 comprises two, four, orsix expansion loops 110.

FIGS. 2A, 2B, and 2C depict some of the features of the “cinched-loop”embodiment of the expandable surgical implant 100. In this embodiment,the expansion loops 110 and 110′ comprise at least one pair of controlelement attachment sites 112 and 112′ positioned away from the centralportion of the implant. The control element attachment sites 112 and112′ may be reinforced, for example with an eyelet 116 and 116′ (asshown in FIG. 2B) or an additional piece of biocompatible material.

The expandable surgical implant may be specifically configured as asling for treating female urinary stress incontinence. In suchembodiments, a first control element attachment site 112 is preferablypositioned a distance ranging from 3 to 20 mm lateral to the centralperpendicular axis 108 of the length of biocompatible material and asecond control element attachment site 112′ is preferably positioned adistance ranging from 3 to 12 mm further from the central perpendicularaxis 108 than the first control element attachment site 112. Inparticularly preferred embodiments, the second control elementattachment site 112′ is positioned a distance of about 5 mm further fromthe central perpendicular axis 108 than the first control elementattachment site 112. The pair of control element sites is preferablylocated on one side of the central perpendicular axis 108 so that theexpansion loop they form is also lateral to the central axis 108, aconfiguration that will minimize damage to the suburethral tissue(including tissue that may have grown into the sling) which may occurwhen the expansion loops is expanded. As shown in FIG. 2B, the implant100 may have a second pair of control element attachment sites locatedon the opposite side of the central perpendicular axis 108.

FIG. 2A shows a pair of expansion loops 110, 110′ cinched with a pair ofcontrol elements 114, 114′. In the cinched-loop embodiments, expansionis accomplished by uncinching the control element 114, which holds thecorresponding pair of control element sites 112, 112′ in closeproximity. FIG. 2C illustrates a cinched loop in which the controlelement 114 has been severed.

Uncinching the control element 114 may be accomplished in severaldifferent ways. The expansion loop may be uncinched, for example, bymechanically severing the control element 114, bioabsorbing the controlelement 114, or decomposing the control element 114 by the applicationof an external stimulus. Thus, the control element 114 may be severed,for example, by using mechanical means such as a scalpel, or it may bebroken down by the body during a predetermined time interval, ordecomposed by localized low energy. Forms of low energy that may be usedto decompose a control element may include, without limitation,ultrasonic waves, radio waves, microwaves, and ultraviolet radiation.

In some embodiments, the control element 114 is a fastener such as amonofilament suture, a multifilament suture, a ribbon of biocompatiblematerial, or a surgical staple. The control element attachment sites 112and 112′ may be reinforced to add resiliency to the expandable surgicalimplant 100 at the expansion loop 110 site or sites. Thus, in someembodiments, the control element attachment sites 116, 116′ may bereinforced with an eyelet (shown in FIG. 2B) or an additional layer ofbiocompatible material. The eyelet may be composed of any), resilientbiocompatible material such as surgical metals and/or polymers.

In some embodiments, the control element 114 may comprise radio-opaquematerials (for example, metals such as stainless steel, superalloys,nitinol, and/or titanium) that may be indirectly visualized (i.e.,without making an incision and/or dissecting to expose the controlelement 114). Such radio-opaque control elements may be visualized, forexample, by fluoroscopy.

In alternative embodiments, the control element 114 may be comprisedentirely of materials with relatively low radio-densities that may notbe indirectly visualizable. In such embodiments, the control element 100may be directly visualized following incision and/or dissection. Tofacilitate direct visualization, the control element 114 may be adifferent color than the length of biocompatible material 102. Directand/or indirect visualization of the control element 114 is particularlyuseful when the surgical implant is expanded after implantation.

FIGS. 3A, 3B, and 3C depict the “stacked-layers” embodiment of theexpandable surgical implant 100. In the stacked-layers embodiment, theexpandable loop comprises multiple layers of biocompatible material ofunequal length. FIG. 3B shows the stacked-layers embodiment wherein theexpansion loop 110 comprises three layers 111 a, 111 b, and 111 c. Inalternative embodiments, the expansion loop 110 may comprise two to sixlayers. Severing, bioabsorption, or decomposition of the shortest of thelayers (i.e., layer 111 c) expands the expandable surgical implant 100.As is shown in FIG. 3C, at least one layer of biocompatible materialshould remain in place after the shortest layer is severed.

In the stacked-layer embodiment, each layer 111 a, 111 b, 111 c of theexpandable loop 110 is preferably about 2 mm to about 10 mm shorter thanthe adjacent longer layer in the stack of biocompatible material. Inparticularly preferred embodiments, each layer of loop 110 is about 5 mmshorter than the immediately overlaying layer of biocompatible materialin the stack. Furthermore, the loop 110 is preferably positioned adistance ranging from 3 to 20 mm lateral to the central perpendicularaxis 108. In particularly preferred embodiments, the loop 110 closest tothe central perpendicular axis 108 is about 6 mm lateral to the centralperpendicular axis 108.

FIG. 4 illustrates embodiments in which a visual indicator 118 isdisposed along the central perpendicular axis 108 of the expandablesurgical implant 100. The visual indicator 118 is a visual guideemployed to align the expandable surgical implant 100 with the damagedportion of the patient's body (e.g., the suburethral portion of theimplant when the implant is used to treat urinary incontinence).Although the visual indicator 118 is shown in FIG. 1 as a pair of brokenlines disposed on either side of the central axis 108 and shown in FIG.4 as a rectangular strip disposed along the central perpendicular axis108, it may be otherwise configured and positioned according to theparticular application.

When the implant is specifically configured as a sling for treatingfemale urinary stress incontinence, the expansion loop 110 of thestacked layers is preferably positioned away from the central portion(e.g., lateral to the central portions) of the surgical implant and thevisual indicator 118 is preferably positioned generally in the centralportion of the expandable surgical implant 100 and in the vicinity ofthe central perpendicular axis 108.

FIG. 4 illustrates an embodiment in which the expandable surgicalimplant 100 further comprises pairs of reinforced fastener attachmentsites 128 a, 128 b. These fastener attachments sites may be used toattach a fastener to the expandable surgical implant 100. Fasteners forsecuring the expandable surgical implant 100 to an anatomical structureof the patient are preferably disposed in the 1 cm region near the endsof the surgical implant 100. The fasteners may be, for example, suturesthat are disposed on the expandable surgical implant 100 by threadingthem through the eyelets 128 a, and 128 b. In alternative embodiments,the fastener may comprise a clip, a bone anchor, a staple, and/or othersuitable fasteners.

The expandable surgical implant 100 may be made of mammalian tissue(s),synthetic material(s), or a combination of mammalian tissue(s) andsynthetic material(s). One or more mammalian tissues including porcine,ovine, bovine, equine, human cadaveric, or tissue-engineered tissue(s)may be employed to make the material. The material may be derived fromomni-directional tissue(s) including dermis and/or pericardium. Suitablematerials for use in accordance with this invention include a chemicallyprocessed acellular human dermis product that preserves, undamaged, thebioactive structural dermal matrix and which is freeze-dried forstorage. The removal of cells from the fully intact dermal matrixreduces the risk of rejection and inflammation and provides a basis forsoft tissue reconstruction. Such an acellular human dermal matrix isavailable from Lifecell (Branchburg, N.J.) under the trade designationAlloDerm® acellular tissue.

Alternatively, oriented mammal tissue(s) including rectus fascia and/orfascia lata may be used for the material. Suitable cleaned andsterilized oriented human tissue materials may be obtained from tissuebanks. These animal tissues may be dehydrated with a dehydrating fluid,such as ethyl alcohol or the like, prior to treatment with chemicalcross-linking agents, to allow for improved penetration. Thecross-linking agent cross-links collagen in the tissues to make thetissues stronger and reduce the antigenicity of the tissues. Otheragents such as pepsin may also be used to further reduce antigenicity.The tissues may be cross-linked by using one or more of the followingtreatment agents: glutaraldehyde, dialdehyde, glutaraldehyde starch,dialdehyde starch, an epoxy compound or ionizing radiation. Certainprocesses (such as heat, radiation or pH change) or agents (such ashalogens, enzymes, organic solvents, detergents, sodium hydroxide,hydrochloric acid, sodium hypochlorite or hydrogen peroxide) may be usedto inactivate viruses with and without protein coats or to destroy viralagent infectivity during the manufacturing process. The tissue may alsobe treated with a highly volatile chemical such as, for example,propylene oxide, to assist with the sterilization of the tissue.Sterilization may be accomplished, for example, using one or more of thefollowing treatments: glutaraldehyde, alcohol, propylene oxide orirradiation sterilization. The treatment of the tissue, with acombination of these materials and processes, can both cross-link thetissue and render the tissue sterile for installation inside the body ofa patient.

The synthetic material may be a solid material, a weave, a braid, a meshor an alternate material construction. The synthetic material may be apolymer. Suitable polymer sources include nylon, polyethylene,polyester, polypropylene, fluoropolymers or copolymers thereof. Anexemplary synthetic polyester material suitable for use in according tothe invention is available under the trade designation Dacron®, from E.I. du Pont de Nemours and Company (Wilmington, Del.). Other suitablesynthetic materials include the fluoropolymers polytetrafluoroethylene(PTFE), which has non-melt processible characteristics, and fluorinatedethylene propylene (FEP), which has melt-processible characteristics;both fluoropolymers are available under the trade designation Teflon®,from E. I. du Pont de Nemours and Company (Wilmington, Del.). A suitablePTFE material of solid material construction is a available under thetrade designation GORE-TEX®, from W. L. Gore & Associates, Inc.(Flagstaff , Ariz.).

Combinations of synthetic materials and mammalian tissues may also beused according to the invention. These combinations may include materialhaving a combination of parts, including, for example, parts made ofsynthetic polymers and of processed animal tissues. Such combinationsalso include materials having both synthetic polymers and animal cellsthat are treated so as to cross-link the collagen or other commonlyantigenic fibers in the animal cells. When a combination of syntheticmaterials and natural materials is used, it is preferred, but notnecessary, that the central portion comprise natural materials and theend portions comprise synthetic materials.

The material is provided in a shape suitable for a medical application,e.g., rectangular, and may include elongated members extending from acentral portion of the material. Other suitable shapes may includeoctagonal, trapezoidal, elliptical and hexagonal shapes. When thesurgical implant is specifically configured as sling for use in treatingfemale urinary stress incontinence, the biocompatible material 102 mayhave a length from about 2.5 cm to about 30 cm in length and a widththat ranges from about 1.0 cm to about 3.0 cm.

The expandable surgical implant 100 may be sterilized and packaged in asterile holder. The packaging conditions may be dry and the packageprotective of the expandable surgical implant 100 during transport andstorage. The packaging may be designed to protect the material of theexpandable surgical implant 100 from ultra-violet light to preventdamage. Upon opening the protective package, the implant may behydrated, if necessary, with, for example, saline solution, andthereafter installed in the patient without any additional alteration bythe surgeon performing the surgical procedure.

As will be described in further detail below, the forgoing expandablesurgical implants 100 are particularly useful in surgical methods thatrequire minimal invasion (i.e., incision and/or dissection) to expand asurgical implant that has been placed within a body.

In one embodiment, a method of treating a damaged portion of a patient'sbody employs the expandable surgical implant 100 of the invention. Themethod includes, in overview, providing the expandable surgical implant100; positioning the central perpendicular axis 108 axis of implant isso that it lies substantially along a portion of the patient's body tobe supported (e.g., the urethra); (optionally) securing the first end104 of the material of the implant to a first anatomical structure inthe body of the patient; applying tensioning force substantially alongthe longitudinal axis of the material; (optionally) securing the secondend 106 of the material to the same or a second anatomical structure inthe body of the patient; supporting a damaged portion of the patient'sbody with the secured material; and expanding one or more expansionloops 110 on the implant to relieve excessive tension.

As described in greater detail above, the expanding step may result fromdecomposition or severing of a control element or stacked layer.Furthermore, a single expandable surgical implant 100 may comprisemultiple expansion loops that may be uncinched separately, usingdifferent techniques, providing a physician with the ability toincrementally expand the implant according to the patient's needs.

In one particular embodiment, the expandable surgical implant 100 isemployed to treat a female patient suffering from stress urinaryincontinence. FIGS. 5-7 show various options available for placement ofthe medical device of the invention to treat female urinaryincontinence. These figures show a sagittal view of a female pelvisincluding the pubic bone 130, the urethra 134, and the vaginal canal132. Physiological conditions that cause stress urinary incontinence mayinclude ISD, bladderneck hypermobility, and a combination of the twoconditions. When an expandable surgical implant 100 is employed to treatincontinence, it may be used to provide support to the pelvic floor.Where the physiological condition is ISD, the expandable surgicalimplant 100 may be installed to improve improper coaption of theurethral sphincter. Alternatively, where the condition is hypermobility,the expandable surgical implant 100 may be installed to support, elevateor “back stop” the midurethra. In the patient who suffers from acombination of ISD and hypermobility, an expandable surgical implant 100may be installed to support one or an of these sites.

In general, approaches to access the body to deliver and installsurgical implants for treating female stress incontinence includetransvaginal, transabdominal, and combined transvaginal andtransabdominal procedures. In some procedures, the expandable surgicalimplant 100 may be secured to an anatomical structure. A variety offasteners may be used to secure the implant including bone anchors,staples, bone screws , and/or sutures.

In methods employing a transvaginal approach, an anchor implantationdevice may be introduced directly through the vaginal wall or,alternatively, through an incision in the anterior vaginal wall. Aleading edge of an anchor implantation device may be passed through theanterior vaginal wall to the side of the bladder neck, and a bone anchormay be, optionally, secured to the posterior aspect of the pubic bone(shown in FIGS. 5-7). In other embodiments the implant may be secured toother anatomical structures such as the Cooper's ligament. Inalternative embodiments, the implant may be placed within the bodywithout being secured to an anatomical structure. After the implant 100is position in the body and, optionally, an anchor is driven into thepubic bone, the anchor implantation device is withdrawn and removedleaving the two free ends of suture exiting the endopelvic fascia andtrailing the two free ends of the suture from the vaginal wall incision.The above procedure is repeated on the opposite side of the urethra toimplant a second anchor.

The expandable surgical implants 100 disclosed herein are designed to besecured to any suitable support structure of a patient's body. Examplesof such structures include but are not limited to the bones, ligaments,fascia and appropriate muscle structures proximate to the site ofattachment. For example, sutures may be used to attach the implant tothe Cooper's ligament or the rectus fascia without using a bone anchor.

In some embodiments, the anchor implant site is located lateral to thesymphysis pubis and cephalad to the inferior edge of the pubic bone asshown in FIG. 5. In one particular embodiment, the anchor implant siteis located approximately 1 cm lateral to the symphysis pubis and 1 cmcephalad to the inferior edge of the pubic bone. In an alternativeembodiment, the expandable surgical implant 100 may be anchored to theposterior surface of the pubic bone mid-way between the inferior andsuperior surfaces as is shown in FIG. 7. In yet another alternativeembodiment, the expandable surgical implant 100 may be anchored thesuperior surface of the pubic bone as is shown in FIG. 7.

Following installation inside the patient, cells infiltrate the opensurface areas of the expandable surgical implant 100 and tissue growthbegins. The tissue on both sides of the implant cross communicates suchthat tissue from both the anterior vaginal wall and urethra grows intothe expandable surgical implant 100. This scar tissue growth providessupport to the urethra. This tissue growth also secures the implant atthe site of installation, thus improving urethra closing pressure andpatient continence.

Regardless of the method or the site of implantation, the expandablesurgical implant 100 of the invention may be expanded one or more timesfollowing implantation. Thus, if the implant was placed too taut or ifthe patient's anatomy changes due to aging, weight gain, and/orpregnancy the expandable surgical implant 100 of the invention may beexpanded to restore a proper tension. For example, the expandablesurgical implant 100 of the invention may be expanded post-operatively afirst time in the first several weeks following the procedure bysevering (e.g., with a scalpel) the expansion loop 110. Subsequently, asecond expansion may be accomplished by applying a localized stimulus(ultrasonic waves) to decompose a second expansion loop 10. A thirdexpansion may be accomplished by applying a different localized stimulus(e.g., microwave radiation) to decompose a third expansion loop.

In all embodiments, the expansion loop 110 may be uncinched directly(e.g., mechanically) or indirectly (e.g., using low energy radiation)thereby expanding the implant with minimal invasion. However, insuburethral sling procedures employing embodiments in which theexpansion loop 110 is positioned greater than 6 mm lateral to thecentral perpendicular axis 108, the expansion loops 110 are preferablyuncinched indirectly (e.g., using low energy radiation) thereby avoidingthe need to dissect tissue to access the expansion loop 110. Inembodiments where the expansion loop 110 is positioned 3 to 6 mm lateralto the central perpendicular axis 108 the expansion loop 110 may beuncinched by directly (e.g., mechanically) or indirectly (e.g., usinglow energy radiation) uncinching the expansion loop with minimalinvasion.

In embodiments wherein the control element 114 is radio-opaque, thecontrol element 114 may be visualized using a device such as afluoroscope to confirm that the control element 114 has been severed andthe expansion loop 110 has been uncinched.

As is shown in FIG. 8, the expansion loops 110 a-110 h are preferablypositioned away from the central portion 108 of the expandable surgicalimplant 100 so as to provide maximum suburethral 134 support. As isfurther shown in FIG. 8, a expandable surgical implant 100 used insuburethral sling procedures preferably comprises and even number ofexpansion loops thereby permitting the physician to evenly loosen of theexpandable surgical implant 100 on both sides lateral to the centralperpendicular axis 108 and thereby reduce damage to suburethral tissuethat has grown into the central portion of the implant.

Variations, modifications, and other implementations of what isdescribed herein will occur to those of ordinary skill in the artwithout departing from the spirit and the scope of the invention.Accordingly, the invention is not to be limited only to the precedingillustrative description.

1. An expandable surgical implant comprising a biocompatible materialhaving a first end, a second end positioned opposite to the first end,and a central perpendicular axis located substantially equidistant fromthe first and second ends, and further comprising at least one expansionloop positioned lateral to the central perpendicular axis. 2-50.(canceled)